I have a T3i and mostly likely will upgrade to a full frame one day,,, why wouldnt I? but more to the point, if you can only have three lense, which would you get, with a budget of $ 1500 per lens. thanks

24-105mm f4L IS USM - (standard zoom, wide enough for landscape and generally good zoom range)
Canon 70-200mm f2.8 IS USM II (It's a little bit more than $1500 but couldn't leave it out. Very sharp and fast. Amazing for portrait and sports. In my opinion the best lens canon makes. My friends just got one... very jealous )

I think those two lenses would be able to handle most situations but could also add either a 16-35mm f2.8L or 100mm f2.8L Macro.

50mm 1.2L, 50mm 1.2L, and 50mm 1.2L. Well, OK, I love a 50mm, and could live with just that focal length, but, if limited to only three lenses, perhaps none should be 50mm.

When I shot only with cropped-frame Canons, I managed to do just about everything with my 100mm 2.8L, 35mm 1.4L, and 10-22mm EF-S. Now that I have added a 5D, but kept my cropped-frame Canons, not much has changed, yet. My 10-22mm cannot be used on the 5D, but otherwise, these three lenses could still meet most of my needs. I could rent (hire) a long telephoto lens, or an L portrait lens, as needed.

I could replace the 10-22mm with a 16-35L or 17-40L, in order to have a wide zoom that could be used on the 5D, but this lens does so well on a 7D, I see no reason to change anything yet.

One good thing about having both cropped-frame and full-frame camera bodies is that EF prime lenses can function as two different lenses, being wider on the full-frame body.

3 lenses... I think my current lenses, hmm what are my 3 most used lenses.

Canon 24-70mm 2.8L (for all around, some macro) $1,300
Canon 85mm 1.2L II (mainly portraits and to get the bokehlicious shots) $1,900
Canon 300mm 2.8L IS (great for sports and wildlife, can also be used for portraits) $4,600

But I think I'll be passing the $1,500 barrier right there >.<

_________________http://www.AnderssonPhoto.com Equipment: A blend of Canon, Nikon, Yashica, Leica, Voigtlander, Samyang and Sigma. All of which you can see on my website!Wishlist: Leica M 240, Summilux 50 ASPH, Summilux 24 ASPH